While TEX typesetting can be done easily on your desktop via your favourite program based on the idea, it isn't so on the web.
Of course, there are ways to get this done. You could use the popular jsMath, a JavaScript package which transforms your TEX code into beautiful equations using various fonts and images. You could also use sites such as Code Cogs where you can produce equation images which can then be included into your blog post. These methods however, often require extra processing client-side, and/or more time spent on producing the intended result.
I will talk about a very easy method of doing an equivalent of the above.
Here's the Schrödinger equation for a taster:
i\hbar\frac{\partial\psi}{\partial t} = \frac{\hbar^2}{2m}\nabla^2\psi + V(\mathbf{r})\psi
